Induction of oral stereotypy following amphetamine microinjection into a discrete subregion of the striatum.

Amphetamine and other psychostimulant drugs induce perseverative motor behavior in rodents, such as compulsive sniffing, licking and biting. Although it is known that this behavior, termed stereotypy, is a consequence of dopaminergic stimulation of the striatum, the precise localization of the site of activation is unclear. It is reported here that microinjection of amphetamine (20 micrograms/0.5 microliter) into a circumscribed subregion of the striatum specifically produces intense oral stereotypy. It is proposed that this region, which corresponds to a small area within the ventrolateral striatum, contains motor circuitry critical to oral behavior, including feeding. The behavior elicited by amphetamine-induced stimulation of this area may represent a simple animal model in which to study certain orofacial dyskinesias.